Mycoplankton have so far been a neglected component of pelagic marine ecosystems, having been poorly studied relative to other plankton groups. Currently, there is a lack of understanding of how ...mycoplankton diversity changes through time, and the identity of controlling environmental drivers. Using Fungi-specific high-throughput sequencing and quantitative PCR analysis of plankton DNA samples collected over 6 years from the coastal biodiversity time series site Station L4 situated off Plymouth (UK), we have assessed changes in the temporal variability of mycoplankton diversity and abundance in relation to co-occurring environmental variables. Mycoplankton diversity at Station L4 was dominated by Ascomycota, Basidiomycota and Chytridiomycota, with several orders within these phyla frequently abundant and dominant in multiple years. Repeating interannual mycoplankton blooms were linked to potential controlling environmental drivers, including nitrogen availability and temperature. Specific relationships between mycoplankton and other plankton groups were also identified, with seasonal chytrid blooms matching diatom blooms in consecutive years. Mycoplankton α-diversity was greatest during periods of reduced salinity at Station L4, indicative of riverine input to the ecosystem. Mycoplankton abundance also increased during periods of reduced salinity, and when potential substrate availability was increased, including particulate organic matter. This study has identified possible controlling environmental drivers of mycoplankton diversity and abundance in a coastal sea ecosystem, and therefore sheds new light on the biology and ecology of an enigmatic marine plankton group. Mycoplankton have several potential functional roles, including saprotrophs and parasites, that should now be considered within the consensus view of pelagic ecosystem functioning and services.
Although first described in 1880, Kryptolebias marmoratus avoided scientific scrutiny until 1961, when it was identified as the only known selfing hermaphroditic vertebrate. The subsequent intense ...interest in this fish as a laboratory animal, continuing to this day, might explain the paucity of wild collections, but our collective knowledge now suggests that the inherent difficulty of wild collection is more a matter of “looking in all the wrong places.” Long thought to be rare in the mangroves, and it is rare in certain human-impacted habitats, K. marmoratus can be quite abundant, but in microhabitats not typically targeted by ichthyologists: ephemeral pools at higher elevations in the swamp, crab burrows, and other fossorial or even terrestrial haunts. Field studies of this enigmatic fish have revealed almost amphibious behaviors. During emersion these fish tolerate extended dry periods. In water, they are exposed to temperature extremes, high levels of hydrogen sulfide, and depleted dissolved oxygen. Finally, their catholic diet and a geographically variable sex life completes a portrait of an unusual animal. A clearer picture is emerging of adult life, with initial population density estimates now known and some indication of high population turnover in burrows, but juvenile habitat and adult oviposition sites remain unknown.
Lead halide perovskites are a remarkable class of materials that have emerged over the past decade as being suitable for application in a broad range of devices, such as solar cells, light‐emitting ...diodes, lasers, transistors, and memory devices. While they are often solution‐processed semiconductors deposited at low temperatures, perovskites exhibit properties one would only expect from highly pure inorganic crystals that are grown at high temperatures. This unique phenomenon has resulted in fast‐paced progress toward record device performance. Unfortunately, the basic science behind the remarkable nature of these materials is still not well understood. This review assesses the current understanding of the photoluminescence properties of metal halide perovskite materials and highlights key areas that require further research. Furthermore, the need to standardize the methods for characterization of PL in order to improve comparability, reliability, and reproducibility of results is emphasized.
The study of the photoluminescence properties of metal halide perovskites is of great importance for both the fundamental understanding of their photophysics and further optimization of perovskite‐based optoelectronic devices. This review provides an overview of the current state of knowledge related to the photoluminescence of perovskites and highlights the dire need for standardization of characterization methodologies in order to improve the reproducibility, reliability, and comparability of results.
The 'Vascular Depression' hypothesis posits that cerebrovascular disease may predispose, precipitate or perpetuate some geriatric depressive syndromes. This hypothesis stimulated much research that ...has improved our understanding of the complex relationships between late-life depression (LLD), vascular risk factors, and cognition. Succinctly, there are well-established relationships between LLD, vascular risk factors and cerebral hyperintensities, the radiological hallmark of vascular depression. Cognitive dysfunction is common in LLD, particularly executive dysfunction, a finding predictive of poor antidepressant response. Over time, progression of hyperintensities and cognitive deficits predicts a poor course of depression and may reflect underlying worsening of vascular disease. This work laid the foundation for examining the mechanisms by which vascular disease influences brain circuits and influences the development and course of depression. We review data testing the vascular depression hypothesis with a focus on identifying potential underlying vascular mechanisms. We propose a disconnection hypothesis, wherein focal vascular damage and white matter lesion location is a crucial factor, influencing neural connectivity that contributes to clinical symptomatology. We also propose inflammatory and hypoperfusion hypotheses, concepts that link underlying vascular processes with adverse effects on brain function that influence the development of depression. Testing such hypotheses will not only inform the relationship between vascular disease and depression, but also provide guidance on the potential repurposing of pharmacological agents that may improve LLD outcomes.
Sleep has tremendous importance to organizations because of its relationship with employee performance, safety, health, and attitudes. Moreover, sleep is a malleable behavior that may be improved by ...individual and organizational changes. Despite the consequential and modifiable nature of sleep, little consensus exists regarding its conceptualization, and how the choice of conceptualization may impact relationships with organizational antecedents and outcomes. To offer a stronger foundation for future theory and research about employee sleep, this study calculated meta-analytic correlations of sleep quality and sleep quantity from 152 primary studies of sleep among workers in organizations. Analyses revealed that both sleep quality and sleep quantity associated negatively with workload and a number of health, attitudinal, and affective outcomes. Despite their conceptual similarity, notable differences existed in sleep quality and sleep quantity in terms of their relationships to many different correlates. Generally, the relationships between sleep quality and the examined correlates were stronger for variables that reflected perceptions. Moderator analyses showed that relationships between sleep quality and quantity may be affected by measurement method and the number of self-report items used, while there is little evidence of the effect of measurement time frame. Findings from this first meta-analytic investigation of the occupational sleep literature have implications for the development of theory about relationships between sleep and work, the measurement of sleep, the identification of organizational correlates of sleep, and the design of interventions intended to improve employee sleep.
We report constraints on spin-independent weakly interacting massive particle (WIMP)-nucleon scattering using a 3.35×10^{4} kg day exposure of the Large Underground Xenon (LUX) experiment. A ...dual-phase xenon time projection chamber with 250 kg of active mass is operated at the Sanford Underground Research Facility under Lead, South Dakota (USA). With roughly fourfold improvement in sensitivity for high WIMP masses relative to our previous results, this search yields no evidence of WIMP nuclear recoils. At a WIMP mass of 50 GeV c^{-2}, WIMP-nucleon spin-independent cross sections above 2.2×10^{-46} cm^{2} are excluded at the 90% confidence level. When combined with the previously reported LUX exposure, this exclusion strengthens to 1.1×10^{-46} cm^{2} at 50 GeV c^{-2}.
The vLAMPS is a human, biomimetic liver MPS, in which the ECM and cell seeding of the intermediate layer prior to assembly, simplifies construction of the model and makes the platform user-friendly. ...This primarily glass microfluidic device is optimal for real-time imaging, while minimizing the binding of hydrophobic drugs/biologics to the materials that constitute the device. The assembly of the three layered device with primary human hepatocytes and liver sinusoidal endothelial cells (LSECs), and human cell lines for stellate and Kupffer cells, creates a vascular channel separated from the hepatic channel (chamber) by a porous membrane that allows communication between channels, recapitulating the 3D structure of the liver acinus. The vascular channel can be used to deliver drugs, immune cells, as well as various circulating cells and other factors to a stand-alone liver MPS and/or to couple the liver MPS to other organ MPS. We have successfully created continuous oxygen zonation by controlling the flow rates of media in the distinct vascular and hepatic channels and validated the computational modeling of zonation with oxygen sensitive and insensitive beads. This allows the direct investigation of the role of zonation in physiology, toxicology and disease progression. The vascular channel is lined with human LSECs, recapitulating partial immunologic functions within the liver sinusoid, including the activation of LSECs, promoting the binding of polymorphonuclear leukocytes (PMNs) followed by transmigration into the hepatic chamber. The vLAMPS is a valuable platform to investigate the functions of the healthy and diseased human liver using all primary human cell types and/or iPSC-derived cells.
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•Choledochal cysts were found to be most strongly associated with both iCCA and eCCA.•Cirrhosis was a significant CCA risk, with a stronger association with iCCA than ...eCCA.•Choledocholithiasis had a stronger association with eCCA than iCCA.•In Eastern countries, cirrhosis and HBV conferred a greater risk of iCCA than in Western countries.•Rising global incidence of iCCA may be linked to increases in T2DM, cirrhosis, alcoholic liver disease and cholelithiasis.
Cholangiocarcinoma (CCA) carries a poor prognosis, is increasing in incidence and its causes are poorly understood. Although some risk factors are known, they vary globally and collectively account for a minority of cases. The aim of this study was to perform a comprehensive meta-analysis of risk factors for intrahepatic (iCCA) and extrahepatic cholangiocarcinoma (eCCA), from Eastern and Western world studies.
A literature search of case-control studies was performed to identify potential risk factors for iCCA and eCCA. Pooled odds ratios (ORs) with 95% CIs and heterogeneity were calculated. Funnel plots were used to assess publication bias, and meta-regression was used to select risk factors for comparison between Eastern and Western studies.
A total of 13 risk factors were selected from 25 case-control studies in 7 geographically diverse countries. The strongest risk factors for both iCCA and eCCA were biliary cysts and stones, cirrhosis, hepatitis B and hepatitis C. Choledochal cysts conferred the greatest risk of both iCCA and eCCA with pooled ORs of 26.71 (95% CI 15.80–45.16) and 34.94 (24.36–50.12), respectively. No significant associations were found between hypertension and obesity for either iCCA or eCCA. Comparing Eastern and Western populations, there was a difference for the association of hepatitis B with iCCA (coefficient = −0.15195; 95% CI −0.278 to −0.025; p = 0.022).
This is the most comprehensive meta-analysis of CCA risk factors to date. Some risk factors, such as diabetes, although less strong, are increasing globally and may be contributing to rising rates of this cancer.
Cholangiocarcinoma (CCA) is a cancer arising in the bile ducts inside (intrahepatic CCA) and connected to the liver (extrahepatic CCA). It is a very aggressive cancer: 95% of patients die within 5 years. CCA rates are increasing globally, but the causes of CCA are poorly understood. The few risk factors that are known account for only a minority of cases. In this study, we found that the strongest risk factors for both intrahepatic and extrahepatic CCA are cysts and stones in the bile ducts, cirrhosis, and hepatitis B and C viruses. Some risk factors for CCA, such as diabetes, although less strong, are increasing globally and may be contributing to rising rates of CCA.
This book argues that Putin's strategy for rebuilding the state was fundamentally flawed. Taylor demonstrates that a disregard for the way state officials behave toward citizens - state quality - had ...a negative impact on what the state could do - state capacity. Focusing on those organizations that control state coercion, what Russians call the 'power ministries', Taylor shows that many of the weaknesses of the Russian state that existed under Boris Yeltsin persisted under Putin. Drawing on extensive field research and interviews, as well as a wide range of comparative data, the book reveals the practices and norms that guide the behavior of Russian power ministry officials (the so-called siloviki), especially law enforcement personnel. By examining siloviki behavior from the Kremlin down to the street level, State Building in Putin's Russia uncovers the who, where and how of Russian state building after communism.
In the pursuit of materials with exceptional mechanical properties, a machine-learning model is developed to direct the synthetic efforts toward compounds with high hardness by predicting the elastic ...moduli as a proxy. This approach screens 118 287 compounds compiled in crystal structure databases for the materials with the highest bulk and shear moduli determined by support vector machine regression. Following these models, a ternary rhenium tungsten carbide and a quaternary molybdenum tungsten borocarbide are selected and synthesized at ambient pressure. High-pressure diamond anvil cell measurements corroborate the machine-learning prediction of the bulk modulus with less than 10% error, as well as confirm the ultraincompressible nature of both compounds. Subsequent Vickers microhardness measurements reveal that each compound also has an extremely high hardness exceeding the superhard threshold of 40 GPa at low loads (0.49 N). These results show the effectiveness of materials development through state-of-the-art machine-learning techniques by identifying functional inorganic materials.
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